def show():
    str = "hello world"
    str2 = "test"
    str3="python"

    print(f"{str}----{str2}----{str3}")

    print("Hello")
    print(" World")
    print("python")


show()

def show2():
    for i in range(100+1):
        #
        if is_prime(i):
            print(i,end=",")


        #
def is_prime(n):
    for i in range(2, n):
        if n % i == 0:
            return False
    return True

#
show2()

print()

num = 100
def show3(a,b):
    global num
    num=num+1
    return a+b,a-b,a*b,a//b

print(show3(10,20))

def fib(n):
    if n <= 2:
        return 1
    return fib(n-1) + fib(n-2)

for i in range(1,20+1):
    print(fib(i),end=",")

def fib2(n):
    a = 1
    b = 1
    for i in range(3,n+1):
        c = a+b
        a = b
        b = c
        print(c,end=",")

